The probem Sometime, the downstream task need to interpret the output of a failed shell task (might be from both stdout and stderr) to handle the the failure properly. In my use case, I use DBTShellTask (which is a subclass of ShellTask) for execute a 

dbt run

 as shell sub-process. I then use another task, called 

parse_dbt_result

, to take the output of the dbt task and handle both success and failure results, such as knowing which models in the dbt-run process failed. When some models fails in a 

dbt run

, those model errors are shown in the stdout, and the shell subprocess returns non-zero exit code (1). The ShellTask raises a FAIL signal without any stdout result. As a result, the 

parse_dbt_result

 task is not able to interpret the log of failed run and not know which model fails, hereby not be able to handle the failure properly. Solution please provide a flag that allows ShellTask to return stdout(or/and stderror) result when the shell process fails and FAIL signal is raised.